Stair-climbing wheel chair



D. E. BRENNER STAIR-CLIMBING WHEEL CHAIR 3 Sheets-Sh 1 Filed May 17 19630,44:- f. BRf/VMSE July 27, 1965 D. E. BRENNER STAIR-CLIMBING WHEELCHAIR 5 Sheets-Sheet 2 Filed May 17, 1963 INVENTOR. But f. Exam/v52 July27, 1965 D. E. BRENNER 3,196,970

STAIR-CLIMBING WHEEL CHAIR Filed May 17, 1963 s Sheets-Sheet s j BYArmqwe'f United States Patent SsALhLEMBlNG Cilr'lLi Dale Brenner, 2912Fine View Drive, York, Fa. Filed May 17, 19%, Ser. No. 231,163 litQlairns. El. 1342-3) This invention pertains to a stair-climbing wheelchair, and, more particularly, to a chair of this type capable of beingadjusted to ascend and descend Stairways of differ ent tread widths andheights.

Conventional invalid chairs have been used for many years and are wellsuited for transportation of invalids over horizontal surfaces, such asfloors. in somewhat recent years, various attempts have been made todevise wheel chairs capable of ascending and descending stairs,particularly with reasonable safety, and especially through theutilization of a minimum amount of either physical or motive energy.Certain of these prior attempts have been quite complex and,accordingly, costly to produce. l-Iotwithstanding this, however, it mustbe recognized that there are relatively wide variations in the widtnsand heights of stair treads in ditferent homes and buildings, whereby aninvalid wheel chair capable of climbing stairs of one size would not beadapted to climb stairs of a different size, i.e., the heights andwidths of stair treads in one dwelli or building, as distinguished fromthose another, it being understood that in each instance, all of thestair treads of a particular or given stair will have the same width andheight.

it is the principal object of the present invention to provide a wheelchair capable of climbing stairs and including propelling means whichare adjustable to render the chair capable of climbing stairs havingtreads of different heights and widths than those of other stairs,within reasonable limits, thereby renderina the chair substantiallyuniversal for use in climbing stairs.

Another object of the invention is to provide the aforementioned chairwith wheel means to be used in normal, horizontal movement of the chairwhen not climbing stairs, said wheel means being mounted so as to berendered inoperable when the propelling means which permit the chair toclimb stairs are rendered operative.

Still a further object of the invention is to include means in theabove-described chair by which the same may be colla ed, at least to alimited extent, transversely, thereby rendering the chair capable ofbeing stored in a small r space than otherwise would be possible, andalso of enabling the chair to be readily placed within a motor vehiclefor use by an invalid occupant of the vehicle when the destination isreached.

Still another object of the invention is to provide the aforementionedtype of chair with power means to actuate the propelling means for usewhen the chair is adapted to climb stairs.

One further object of the invention is to provide a plurality ofpropelling units in the aforementioned type of chair which are spacedlongitudinally of the frame of the chair, fore and aft of the center ofgravity of the seat means or the chair, each unit having a plurality ofstair tread engageable members, which, in their referred embodiment, arenon-rotatable with respect to the engagement thereof with such stairtreads.

Still another object of the invention ancillary to the immediateforegoins objects is to provide said units with spider-like membersrotatable about horizontal axes and having shoe means pivotallyconnected with the outer ends of the arms of the spider-like means so asto be ported in pendent fashion therefrom, the width of t c shoes beingsuilicient to afford firm, fiat engagement of substantial areas with thestair treads.

Still another object of the invention, ancillary to the immediateforegoing object, is to provide connecting means between the spider-likemeans of said units and the shoes pivotally connected thereto so as topermit radial adjustment of the pivots of the shoes with respect to thepivots of the spider-like means, whereby said propelling meansComprising said units are adapted to stairs of reasonably differentheights and widths of treads, as distinguished from those of otherstairs.

Details of the foregoing objects and of the invention, as wel as otherobjects thereof, are set forth in the following speciiicat -n andillustrated in the accompanying drawings comprising a part thereof.

in the drawings:

PEG. 1 is an eXem-p ary side view of a stair-climbing chair embodyingthe principles of the present invention and illustrated in process ofnegotiating an exemplary set of stairs, the wheel means employed durin"horizontal movement of the chair over a floor surface being shown toinoperative position in said view.

2 is a side elevation showin the chair illustrated in FIG. 1 adapted tomovement over a horizontal surface, such as a floor, while thestair-negotiating propelling are disposed in inoperative position;

F 3 is a front view of the chair arranged in the position shown in 2part of the middle portion of the chair being broken away to foreshortenthe view.

FIGS. 4 and 4a respectively are side and rear views of the seat means ofthe chair shown in the preceding View.

PEG. 5 is a top plan view of the chair shown in FIGS. 1 through 3 withthe seat means removed therefrom so as better to illustrate details ofthe power means of the chair.

FIG. 6 is a fragmentary rear end view of the drive shaft which isenergiz d by the power means shown in PEG. 5, the scale employed in EEG.6 being larger than that used in PEG. 5.

FIGS. 7 and 8 respectively are side and end views of one of the sideframe members or" the chair shown in FlGS. 1 through 3.

FIG. 9 is a fragmentary front view of the power pack illustrated on alarger scale than that of FIG. 5 and illustrating the power pack shownin the latter figure.

PEG. it) is a side elevation, partly in section, of the motor and gearreduction unit employed in the drive means shown in FIG. 5.

PEG. 11 is a rear View of a cross strut of the frame of the chair shownin FIG. 5 and by which the motor of the power unit is supported.

FIG. 12 is a fragmentary plan View of part or" the frai e by which thepower pack is supported and illustrated in partially contractedcondition.

FIG. 13 is a fragmentary perspective view of part of the frame mechanismillustrated in FiG. 12.

FIG. 14 is a face view of one of the spider means of a propelling unitand showing a preferred method of adjustably supporting stair-treadengageable shoes thereon.

FIG, 15 is an enlarged fragmentary side elevation of one extremity of anarm of the spider means of the propelling units and illustrating anexemplary shoe adjustably connected thereto.

FIG. 16 is a side edge view of the fragmentary mechanism illustrated inFIG. 15.

PEG. 17 is a fragmentary edge View of the bell crank by which theprincipal supporting wheels for the chair while transversing horizontalfloor surfaces are moved between operative and inoperative position andmaintained in such selected position.

FIG. 18 is a fragmentary enlarged view of the adjust able mounting meansfor the rear supporting wheels em- :plates in detail. and aft bearings32- and 34 to receive bearing shafts for the propelling units 18 and 20.Said side plates, also, in the uppermost portion thereof, including anopen ended bearing notch 36 within which trunnions on the seat unitmeans.

ployed when the chair is negotiating horizontal surfaces, as shown inFIG, 2.

FIGS. 22 and 19 respectively are edge views and face views illustratinga fragmentary portion of the extremity of a bell crank which supportsthe large Wheels employed in FIG. 2 for horizontal movement of thechair.

FIG. 20 is a fragmentary view of part of the frame by which an idler,belt-tensioning roller is adjustably supported for vertical movement.

FIG. 21 is a fragmentary view of the forward portion of the frame whichsupports the drive means for the forward propelling unit.

Referring to FIG. 1, there is illustrated a stair-climbing wheel chairwhich embodies the principles of the present invention and isillustrated in process of traversing a set of stairs 10. In thisillustration, it is not important whether the wheel chair is ascendingor descending the stairs because the only difference is, under suchcircumstances, that the power means is of a reversible nature and iscontrolled by the operator 12 for selective operation in eitherdirection. When transversing the stairs 10, the chair and the operatorare disposed in relationship to the stairs so that the operator facesdownstairs, primarily because, in relation to the construction of thechair, it is more convenient to arrange the propelling means and othersupporting means for the chair in such relationship to the seat of thechair that it is less complicated than if the seat and operator facedupstairs while traversing the stairs.

According to the preferred construction of the present invention, thechair embodying the principles of the present invention includesmechanism which is designated illustrated in stair-negotiatingarrangement and in horizontal surface travel, said chair assemblybasically comprises a frame 16, a pair of longitudinally spacedpropelling units 18 and 20, a seat unit 22, and wheel means -comprisinga pair of forward wheels 24 and, preferably,

a pair of rearwheels 26. The seat unit 22, selectively, may be eitherfixed in its position with respect to frame 16, or pivotally suspendedfrom the upper portion thereof so as to permit the weight of theoccupant or operator 12 to cause the seat to find its own position withrespect to the frame through the operation of gravity.

As will be seen from FIGS. 1, 2 and 7, the frame 16 comprises aplurality of similarly shaped side plates 28 and 30, it being understoodthese respectively are mirror images of each other. In side view, theframe 16 may be considered somewhat to be A-shaped, as is evidentparticularly from FIG. 7 which shows one of the side Each of said sideplates comprise fore 22 are received so as to provide support for saidseat Further, intermediately of the confines of each side plate is stillanother bearing hole 38 provided for purposes of supporting the forwardwheels 24, as described in detail hereinafter.

The opposite side plates 28 and 3d of frame 16 are connected together bya plurality of transverse struts or connecting members, which are bestillustrated in plan view in FIG. 5, wherein only a portion of the chairas sembly is shown, principally comprising the frame 16,

, the propelling units 18 and 2b, and the power mechanism 4 foractuating the propelling units. The transverse connecting means for theside plates comprises an articulated rear connector comprising a pair ofinterconnected plates 4%) and 42, which respectively are connected bybolts, at the opposite ends thereof, to side plates 23 and 30, asclearly shown in FIG. 5. The opposite ends of plates 49 and 42 areconnected together by bolt and Wing nuts .4, the bolt extending throughappropriate hole in plates 42, for example, and plate 46' havinglongitudinal slots 46 therein, which likewise receive the bolts referredto and, when the nuts 44 are loosened, the plates 40 and 42 may beadjusted longitudinally with respect to each other to a limited extent,particularly for purposes of permitting theframe 16 of the chair to becontracted transversely to a limited degree for purposes of facilitatingmore compact storage and transportation of the chair when not in use.

A forward transverse strut also is articulated, especially for purposesof facilitating the contraction of the frame of the chair referred toabove, said strut comprising a plurality of Z-shaped brackets 48, eachof which have one end flange fixedly connected respectively to the frameplates 28 and 3%, as best illustrated in FIGS. 5 and 12. The oppositeends of the brackets 48 are pivotally connected to hinge members 5t and52, said hinge members also being connected together. However, thelatter also may be maintained in transverse position with respect to theframe 16, Within a common plane, by means of a latch member 54, see FIG.5. Hinge member 50 also is provided with a boss 56 from which a mountingstud 58 projects upwardly to pivotally support a power pack 69, forpurposes to be described hereinafter.

Also extending between the opposite side plates 28 and 3th of the frame,intermediately of the front and rear transverse strut means, is alongitudinally contractible drive shaft 62, comprising, for example,complementary elongated socket and shaft members which are axiallyslidable,but are non-rotatable relative to each other, the opposite endsof the drive shaft 62 being supported within bearings 34 within the sideplates 28 and 30, as shown in detail in FIG. 6. The details of thearticulated shaft 62 by which longitudinal expansion and contraction maytake place also is illustrated to advantage in FIG. 6. Further, fromsaid figure, it will be seen that a gear housing 64, which containsreduction gearing specifically illustrated as a worm gear 66 and worm68, as shown in FIG.

6, is associated with power shaft 62, the worm gear 66 being keyedtheretoin conventional manner, and said shaft also extending throughsuitable bearings in opposite sides of the gead housing 64, likewise inaccordance with conventional construction.

Worm 68 is driven by drive shaft 70 of motor 72. A

motor-supporting bracket '74, best shown in FIGS. 5 and 10, is fixed bysuitable bolts, or the like, to plate 42 of the rear strut means. Asuitable electrical conductor 76 extends between power pack 6%? andmotor 72, as well as similarly extending to a control switch 78, shownin FIG. 1, as being mounted conveniently for operation by the hand ofthe occupant 12. Such electrical conductor prefer-ably is flexible andalso is provided with plug and socket connector means to permit readyconnecting and disconnecting of the conductor, when desired.

Particularly from FIG. 5, it will be seen that when the wing nuts 44 onthe rear strut means and latch 54- on the forward strut means areloosened and disconnected respectively, said transverse strut means maybe contracted a limited extent, as can the articulated, telescopicallyarranged drive shafts 62, thereby permitting movement of frame plates 28and 36 toward each other a substantial amount. Such contracting is madepossible particularly due to the pivotally arranged support for thepower pack about the axis of the mounting stud 58, the collapsing of theforward strut, at least to a partial degree, being illustrated inexemplary manner in FIG. 12. When so contracted or collapsed, the frame16 readily may be stored in more compact space, or placed within a motorvehicle in a smaller space than otherwise would be possible if the framecould not be collapsed or contracted.

Frame 16 supports the propelling units it; and as, which respectivelycomprise transversely spaced pairs of spiders 8% one of which is shownin detail in FIG. 14. In the preferred embodiment, each spider isprovided with four arms of equal length and spaced evencircumferentially. The outer end of each arm is provided with a seriesof intersecting holes 82, which comprise means permitting longitudinaladjustment of the arms, in a radial direction with respect to the axisof each spider, whereby stair tread-engaging pads or feet 34 may berespectively connected to the outer end of each arm of each spider. Itis to be understood, incidentally, that the above-described specificmeans for affording longitudinal adjustment of the feet 84 with respectto the outer end of one arm of each spider is merely exemplary andcornprises a relatively inexpensive means for accomplismng suchadjustment simply by suitably positioning pivot bolts 8::correspondingly within a selected hole of the groups of holes 32 in theouter end of each arm of each spider.

Each spider is provided with a hub 88, which is connected by means of atransverse key 99, or other suitable means, either to opposite endportions of the drive shaft 62, or to the inner ends of short driveshafts 92, see FIG. 21, which extend through bearings 32 in the forwardportion of the side frame plates 23 and of frame 16. Also keyed to eachof the short drive shafts 92, as well as to the opposite ends of themain drive shaft 62, are sprocket gears or pulleys 94, which are fixedby keys 95 respectively to the shafts which support said sprocket gears.Also supported within an elongated, vertically extending slot 98 in eachframe plate 23 and 33, see FIG. 7, is an adjustable idler pulley or gearwhich is rotatable about a short shaft 1162, details of which are bestshown in FIG. 20.

Extending around the sprocket gears or pulleys 9 which are pivotallysupported respectively adjacent each of the side plates 23 and 3% of thframe, and also around the idler pulley or gear lid) on each frame, is aflexible sprocket chain or V-belt 1%. In view of the fact that maindrive shaft 92 is driven by the motor 72-, which is energized by powerpack as, the sprocket gears or pulleys 94, which are connected directlyto main drive shaft 62, respectively will drive the sprocket chains orV-belts 1% connected thereto and, as a result, likewise drive theforward spocket gears or pulleys 94 which are connected to the shortdrive shafts $2 to which the spiders it of the forward propelling units13 are connected. The spiders ill of the rearward propelling units 2%,which are connected directly to the main drive shaft 62, as shown inFIG. 6, will be directly driven by said main drive shaft. Hence, throughthe action of the sprocket chains or V- belts ill-l at opposite sides ofthe frame, which chains or belts preferably are maintained relativelytaut through the idler tensioning gears or pulleys laid, it will be seenthat precise orientation of the pads or shoes 84 in the forward andrearward propelling units is and 29 will be maintained, as will bedescribed hereinafter in greater detail.

Supported preferably by the upper portions of each of the side plates 23and 30 of frame 16, within the bearing notches 3% thereof, is apreferably skeleton-like and lightweight seat unit 22, details of whichare best shown in FIGS. 4 and 4a. Said seat unit, in the preferredconstruction, comprises tubular, or other suitable types, of side frames1%, each of said frames including arm plates 3E3. The upper ends of saidside frames also extend rearwardly to provide hand grips lit? by whichan attendant, if desired, may propel the occupant of the chair over ahorizontal surface, such as a floor 112-, when the propelling units areimmobilized and the forward and rearward wheels 24 and 2-6 are placed inoperation, as will be described hereinafter.

. gage successive stair treads, as shown in FIG. 1.

Each of the side frames tee of the seat unit 22, beneath each arm plate1%, for example, is provided with a trunnion 11d and, extending outwardfrom the lower forward end of each side frame we of the seat unit 22 isa foot tread 115 which, if desired, may be pivotally connected to thelower end of each side frame so as to be capable of being folded to amore compact position.

As best seen from FIGS. 1 and 2, there is a flexible back member 116,made from canvas or the like, which extends between the rear uprig itportions of the side frames 1 36 of seat unit 22 and, also extendingbetween the lower horizontal portions of side frames tee is a similarflexible seat member or panel 118. To maintain these back and seatmembers relatively taut, and also otherwise to rigidify the seat unit22, collapsible transverse struts 12d and 122 provided, the location ofthese best being illustrated in Figs. 4 and 4a. It also wil be seen thatportions of said struts are hingedly connected and maintained rigid bysuitable latch members 3'24, which are shown in detail in FlG. 4a. Sucharrangement enables the space side frames ass to be contracted towardeach other, as when the side plates 28 and fill of the frame 16 likewiseare being contracted so as to render the entire chair unit more compactfor storage or transportation.

As best shov n in FIGS. 1 and 2, the seat unit 22 is supported by thetrunnions 114, at opposite sides thereof, being disposed within the openbearing notches 36 in the upper portion of frame 16. By sucharrangement, when the seat unit 22 is occupied by a person, said seatunit and occupant will find its own level and the design of the seatunit, particularly ith the position of the trunnions 31dthereon, is suchthat when the chair assembly is negotiating stairs, as shown in FIG. 1,the center of gravity of the seat unit and occupant is disposed betweenthe effective feet of the longitudinally spaced propelling units it? andif desired, suitable latch means, not shown, may be provided betweenframe 16 and the seat unit 22 so as to hold the seat unit againstpivotal movement about the axes of its trunnions 114, if desired,especially when the chair is negotiating a horizontal surface, such asshown in FIG. 2, when the wheels 24 and as are employed in lieu f thepropelling units 18 and 2t).

When the chair assembly is negotiating a flight of stairs it), either inascending or descending movement, it can be seen that, at four timesduring each revolution of the spiders 36 of each of the forward andrearward propelling units, two of the pads or feet 84 on each spiderwill en- This situation only occurs momentarily, however, and,immediately thereafter, only one foot 84 on each spider will engage astair tread, but, even under such circumstances, transverse pairs ofsuch feet 84 will engage the same stair tread. Accordingly, at no timewill less than four of the feet 34, arranged substantially in a square,in plan view, he in contact with longitudinally spaced stair treadsbetween which the center of gravity of the occupant of the chair will bedisposed so as to assure ample support and steady movement of theoccupant either up or down the stairs.

To insure that the above-described re ationship of the pads or feet 34with respect to the stair reads will occur, and assuming that all of thestair treads in any particular set of stairs are of equal width and therisers are of equal height, the effective length of each arm of eachspider may be adjusted in view of the series of intersecting holes 82,for example, or other equivalent means, by which the required ef ectivelength of each arm of the spiders may be determined so as to insuresubstantially the same position of engagement between each of the feet34- and the succesive stair treads of any given set of stairs. Sucheffective length of the arms of the spiders 8d normally would bedetermined at the time the chair is new, for example, and is beingadapted to a specific set of stairs, or, in the event the chair is takento a new location where the width of the treads or height of the risersof the stairs is different from that for which the setting previouslyhas been arranged, then a readjustment of the feet with respect to thespiders will be required. Unless some suitable form of adjustment isprovided, however, it readily can be seen that any fixed relationship inregard to the effective length of the spider arms would enable the chairto be used only on one particular stair arrangement for which that giveneffective length of the spider arms is adapted for use.

While it is conceivable that the motor 72 can be oper ated at suchspeeds that ascent and descent of a set of stairs can be accomplished ina relatively short space of time, it nevertheless is preferred,particularly for purposes of conserving current of any given power pack6%, that 'the propelling units 13 and 20 be utilized only for purposesof negotiating stairs. When the chair is to be used on a horizontalsurface, such as floor 112, the chair is arranged so that a pair ofso-called conventional forward wheels 24 may be lowered from theinoperative position thereof, shown in FIG. 1, to the operativeposition, shown in FIG. 2. Similarly, the pair of so-called conventionalrear wheels 26 may be lowered from the inoperative position shown inFIG. 1, in which they also are clearly out of contact with any of thestairs, to the operative position thereof shown in PEG. 2.

When the wheels 24 and 26 are so lowered to their operative position, asillustrated in FIG. 2, it will be seen that the feet 84 of thepropelling units 18 and 29 are at least slightly spaced above the floorsurface 112, whereby they will not contact the same. Further, especiallyas is clearly evident from FIG. 5, the pads or feet 34 preferably arerelatively narrow in a transverse direction, thereby affording ratherample space between the inner edges thereof and providing ready means bywhich a person who is to occupy the chair may approach the seat of thesame, or be carried, so as to be disposed within said seat. It also ismentioned that, for purposes of simplification, FIG. does not illustratethe wheels 24 and 26, or the mounting means therefor; nor does itillustrate the seat unit 22.

The forward wheels 24, which are of substantial diameter and of thenormal wheel-chair type having manual propelling means, are individuallyrotatably supported upon a short shaft 126 extending transversely fromone end of a bell crank 123. One bell crank is connected to rounds theshaft and exerts pressure in a direction to hold the bearing sleeves 142against the bosses 145.

When the chair is disposed in the position shown in FIG. 2, whereby therear wheels 25 are in operative position, they are maintained in suchposition by means of any suitable indexing means, such as a pin 150,which preferably is fixed to boss 146, while the outer end thereof isreceivable within a complementary hole 152 provided in each bearingsleeve 142. The springs 148 will serve to maintain the pins 15% withinthe holes 152.

Preferably, the sleeves 142 each are provided with a second hole 154-,see FIGS. 7 and 18, which also is capable of receiving the outer end ofindexing pin 15%? when the spring 143 is compressed and the bearingsleeve 142 is revolved about the axis of shaft 144, through manipulationof suitable handle 156, until the bearing sleeves 142 and the wheelassemblies carried thereby are disposed in the position shown in FIG. 1,which is the inoperative position of the rear wheels 26. When thisposition is reached, each of said rear wheels will be maintained in suchposition by engagement of the pins 150 within the second holes 154 ofthe bearing sleeves 142, and the springs 145 will maintain suchengagement of the pins and holes. It also will be seen that the handles156 are positioned for relatively easy engagement by the hands of theoccupant of the chair for manipulation between operative and inoperativepositions.

While the invention has been described and illustrated in its severalpreferred embodiments and has included certain details, it should beunderstood that the invention is not to be limited to the precisedetails herein illustrated and described, since the same may be carriedout in other said frame fore and aft of the center of gravity of saideach of the side plates 28 and 30 of frame 16, intermediately of itsends, upon a short pivot 136, one of which is shown in FIG. 17.Preferably, the opposite arm or end of each bell crank 128 is relativelylong and terminates in a handle 132, which, conveniently, is engage ableby the occupant of the wheel chair so that he may manipulate the wheels24 between operative and inoperative positions. bell cranks preferablyis somewhat flexible, thereby permitting the outer ends of said longerarms of the bell crank to move a limited extent laterally outwardlyfromoperative position, as shown in FIG. 2, whereas when the longer armsof the bell cranks 128 are snapped rearwardly behind the uppermost lugs136, as shown in FIG. 1, the wheels 24 will be maintained, against theaction of gravity, in the inoperative positions thereof.

The rear wheels 26 preferably are mounted in yokes 138 having verticalshafts 145), which are swiveled within bearing sleeves 142 provided withshort supporting shafts 144 extending laterally therefrom and projectingthrough bosses or pads 146 provided on the rear, lower corners of sideplates 28 and 31), as best shown in FIGS. 5, 7, 8 and 18. Preferably,the outer end of each supporting shaft 144 is headed and a compressionspring 143 sur- Further, said longer arm of each of the seat meansthereon, a plurality of stair step-enageable members pivotally supportedin pendant manner by said propelling means and having flat surfacesengageable with the treads of spaced stair steps, means adjustablyconnecting said members to said propelling means to adapt said membersfor engagement with stair trends of different heights and widths, andmeans to actuate said propelling means and members supported thereby.

2. The stair-climbing wheel chair according to claim 1 in which thecenter of gravity of said seat means when occupied by a person willshift between forward and rearward positions relative to said frame bypivotal movement of said seat means about the apex of said frame whileremaining between the forward and rearward ends of said frame.

3. The stair-climbing wheel chair set forth in claim 1 furthercharacterized by said units comprising pairs of transversely spacedspider members and said stepengageable members are feet members havingflat sur faces normally extending lowermost and horizontal andengageable with stair treads successively.

4. The stair-climbing wheel chair set forth in claim 3 furthercharacterized by said spider members being supl ported by said frame forrotation about axes extending transversely of said frame and each membercomprising a plurality of radially extending arms, and means pivotallyconnecting said feet members to said arms of said spider. members, thepivot means for said feet members amass o fore and aft of the center ofgravity of said frame and all of said wheel means being supported bysaid frame for movement between lowered operative position forengagement with a floor surface and raised inoperative position out ofengagement with such floor surface, said wheel means when in loweredoperative position elevating said frame and stair step-engageablemembers above the lower portions or" said wheel means to preventengagement of said step-engageable members with such floor surface.

6. A stair-climbing wheel chair comprising in combination, a framesubstantially A-sliaped in side elevation, seat means supported by theapex of said frame for pivotal movement between two operative positions,propelling means supported by the lower portion of said frame andmovable relative to said frame and comprising a plurality of spiderunits spaced fore and aft of the center of gravity of said seat meanswhen in stair-climbing position, a plurality of members respectivelypivotally supported by the arms of said spider units and having flatfeet members successively en ageable with spaced treads of steps whenclimbing or descending the same, means to actuate said units to propelsaid chair up and down Stairways, forward wheel means supported by saidframe intermediately of said spider units and rear wheel means supportedrear wardly of said units, means supporting said forward and rearwardwheel means for movement between lowered operative position forengagement with a floor surface and raised inoperative position out ofengagement with such floor surface, said wheel means when in loweroperative position elevating said frame and stair step-engageablemembers to prevent engagement of said me. bars on said units with suchfloor surface.

7. The stair-climbing wheel chair set forth in claim 6 further includingmanually operable means interconnected to said wheel means and arrangedto move said wheel means between operative and inoperative positions.

' 8. The stair-climbing wheel chair set forth in claim 7 1Q furthercharacterized by said manually operable eing handles movable relative toposition-maintaining nernbers to hold the selected positions of saidhandles.

The stair-climbing chair according to claim 6 in which said meanssupporting said forward wheel means comprises a bellcrank pivotailysupported by opposite sides of said A-shaped frame, one leg of eachbellcrank having bearing means supporting said wheel means and the otherleg of each bellcranlr extending upwardly from the pivots of saidbellcranlrs and comprising handles readily engsgeable by an occupant ofsaid chair to raise and lower said forward wheel means between elevatedinoperative position and floor engageable positions.

It The stair-climbing chair according to claim 9 further includingposition-maintaining means on said frame engageable by said handle legsof said bellcranks and operable respectively to maintain saidbellcranlrs in position to maintain said forward Wheel means in saidoperative and inoperative positions.

References Cited by the Examiner UNETED STATES PATENTS 1,263,726 4/18Altgelt -8 1,551,127 8/25 Whyel 288-5 2,460,824 4/46 Jackson 186-82,736,564 2/56 Loam et al 280-526 2,798,565 7/57 Rosenth-al et a1.180-65 2,931,449 4/60 King 188-8 3,127,188 3/64 Greub 280-522 3,133,7425/64 Richison et a1. 289-528 3,142,351 7/64 Green 189-8 FOREIGN PATENTS187,291 7/07 Germany.

B. HERSH, Primary Examiner.

LEO FRIAGLIA, Examiner.

1. A STAIR-CLIMBING WHEEL CHAIR COMPRISING IN COMBINATION, A FRAME SUBSTANTIALLY A-SHAPED IN SIDE ELEVATION AND HAVING SIMILAR OPPOSITE SIDES, SEAT MEANS PIVOTALLY SUPPORTED ADJACENT THE APEX OF SAID FRAME AND BETWEEN SAID SIDES THEREOF FOR MOVEMENT BETWEEN A PLURALITY OF OPERATIVE POSITIONS, PROPELLING MEANS ROTATABLY SUPPORTED BY THE LOWER PORTION OF SAID FRAME AND COMPRISING A PLURALITY OF UNITS RESPECTIVELY SPACED LONGITUDINALLY OF SAID FRAME FORE AND AFT OF THE CENTER OF GRAVITY OF SAID SEAT MEANS THEREON, A PLURALITY OF STAIR STEP-ENAGEABLE MEMBERS PIVOTALLY SUPPORTED IN PENDANT MANNER BY SAID PROPELLING MEANS AND HAVING FLAT SURFACES ENGAGEABLE WITH THE THREADS OF SPACED STAIR STEPS, MEANS ADJUSTABLY CONNECTING SAID MEMBERS TO SAID PROPELLING MEANS TO ADAPT SAID MEMBERS FOR ENGAGEMENT WITH STAIR TREADS OF DIFFERENT HEIGHTS AND WIDTHS, AND MEANS TO ACTUATE SAID PROPELLING MEANS AND MEMBERS SUPPORTED THEREBY. 